Everyone seems to be being really tactfula dn nice and all that rubbish, but quite franklly it doesnt seem to be working...

You live with them dont you? I understand that that will make things difficult but you really need to put your foot down - this is not about their feelings, or even them understanding whats going on - its YOUR DAUGHTERS HEALTH AND WELL BEING at stake here.

You are the parent, step up and lay down the law - tell them to STOP FEEDING HER AND STOP GIVING HER DRINKS. FULL STOP. nothing more, nothing less. If they have a problem with that then its just their tough luck. You need to do whats best for your daughter, and its not them.

Sorry ...ymo, but if you let them keep doing it, they are going to walk all over you and your parenting forever.

Good luck!